This invention relates generally to a folder apparatus for folding sheet of material, and more particularly concerns an improved knife folder.
In the field of sheet material handling, folders are well known. Oftentimes, it is desirable to place one or more folds in a sheet or a plurality of sheets. Typically, the sheets may be made of paper, plastic, fabric or some other material. The folders have been developed to automate the folding process and thus obtain operational efficiencies over manual methods which tend to be labor intensive, costly and slow. There are two primary methods of generating folds in paper. These are commonly called xe2x80x9cbuckle foldingxe2x80x9d and xe2x80x9cknife foldingxe2x80x9d. In the mail preparation field, buckle chute folders and knife folders are well known.
Typically, a buckle chute folder comprises two or more fold rollers operating in cooperation with one or more buckle chutes and deflectors to place a sequence of folds in one or more sheets. A conventional buckle chute also includes a stop which is adjustably positioned within the chute for folding the sheets at a particular dimension or distance from the leading edge of the sheet. In operation, a first pair of rollers feeds a stack of sheets (or a single sheet) into the first buckle chute. When the leading edge of the stack hits the stop in the chute, forward progress of the stack ceases. However, the first pair of rollers continue to feed the stack causing a buckle to form in a predetermined location along the length of the stack near the entrance to the buckle chute. As the buckle grows, it enters the nip between another pair of rollers which are positioned adjacent the predetermined location. These rollers fold the stack along the buckle and feed the stack out of the buckle chute. This process is then repeated in subsequent downstream buckle chutes to produce more than one fold in the stack.
Typically, knife folders 1, as shown in FIG. 1a, work by registering one or more sheets S adjacent a pair of fold rollers 2, 4 by contacting an edge of the sheet S against a stop 6 and deflecting the sheet S into a fold nip using a moving knife edge bar 8 which is moved in the direction A as shown in FIG. 1a. 
Buckle chute folders and knife folders are typically used in conjunction with mail processing systems which automatically insert folded sheets into envelopes. Common types of sheet folds are C folds, Z folds shown in FIGS. 1b and 1c and can be performed using typical folders described above. With the C fold, sheets are folded twice as shown in FIG. 1b. With the Z fold, sheets are folded twice in a Z configuration as shown in FIG. 1c. A Z fold may be used when an address is desired to be indicated through the window of a window envelope (not shown). Buckle chute folders use a bend in the feed path in order to start a buckle in the sheet that is to be folded.
Typically when a folder is used for various types of folds such as, for example C, Z or half-sheet folds, the folder will need manual adjustments and the sheet will need to be loaded in various configurations in a tray dependent upon the desired fold. Therefore a user or operator would have to make manual mechanical adjustments for each change. Thus, a folder is needed which is easy for a user or operator to use to make various folds.
The addition of a folder to an apparatus such as an inserter typically means that sheets fed through the apparatus will be folded for insertion. However, an operator may want to insert sheets that are not folded. Therefore, it is desirous to have a folder that can be bypassed so that unfolded sheets can be fed. In order to not fold the sheet it is desirous to not have a fixed bend in the feed path.
Thus there is a need for a folder which substantially overcomes the disadvantages and drawbacks associated with the prior art folders. Particularly, there is a need for a folder having the ability to fold various configurations with reduced adjustment. There is also a need for a folder that can be bypassed for flat sheet feeding.
This invention overcomes the disadvantages of the prior art by providing a folder which can be used to create various folds with reduced mechanical adjustments. The folder can also be bypassed so that an unfolded sheet may be fed downstream. A tray can also be loaded in the same orientation for various folds, allowing an operator to change the application without having to make any manual mechanical adjustments to folder. Thus the folder is easier for the casual operator to use.
This invention relates generally to a folder apparatus for folding sheets of material, and more particularly concerns an improved knife folder. In an embodiment of the present invention, the folder 10 comprises a first fold roller and an input or first idler roller which together define a first nip for feeding a sheet S along an input feed path FI. A second nip is defined by a second fold roller positioned adjacent to the first fold roller. The second nip is configured to feed the sheet along an output or downstream feed path Fo. The folder also includes an inducer or knife folder which comprises a movable body repositionable between at least a first position (inducer in) and second position (inducer out), at least one inducer idler roller (second idler roller) attached to the body. In the first position (inducer in), the second idler roller and the second fold roller form a nip.
The inducer further comprises a blade positioned adjacent to the inducer or second idler roller. A first side of the blade and the first fold roller define a portion of the feed path FD adjacent to the first fold roller when the inducer is in the first position (inducer in). The portion of the feed path FD helps to deflect the sheet into the nip between the first fold roller and the second fold roller. When the inducer is in a second position (inducer out), an auxiliary feed path Fa is formed and whereby the sheet may travel along the auxiliary feed path Fa and subsequently be buckled by the blade when the inducer returns to the first position (inducer in).
The design of the inducer allows the sheet to be fed from the sheet feeder until it reaches the correct position. The inducer is then actuated to force a buckle into the fold nip. The fold system drives the sheet through the fold system until the loose edge passes the tip of the inducer. The fold system is then reversed and the inducer acts as a guide for the sheet into the upper section of the fold system. The inducer can be retracted (inducer out) and the sheet fed to feed path Fa. When in position again, the inducer is actuated again, creating the second fold. The sheet is then driven through the insertion area.
The two fold roller, one inducer system can allow a sheet to be fed from the sheet feeder and up into the clearance path by changing the timing of the inducer to actuate (inducer in) while the sheet is above the fold system. The sheet can then be driven back down and guided by the inducer straight into the fold nip, without creating a fold. This sheet can then be fed through unfolded, into the insertion area, allowing it to be inserted into a flat envelope.
An advantage of the present invention is that it provides a folder which requires less adjustment and which can be bypassed. Another additional advantage of the present invention is that the folder is easier to use by a casual user. Another advantage is that sheets can be placed in trays with the same orientation for various folds. Other advantages of the invention will in part be obvious and will in part be apparent from the specification. The aforementioned advantages are illustrative of the advantages of the various embodiments of the present invention.